<html>
    <head>
        <style>
            *{
                margin: 0;
                padding: 0;
            }
            body{
                width: 300px;
                height: 100px;
            }
            div{
                line-height: 100px;
                font-size: 52px;
                text-align: center;
            }

        </style>
    </head>

    <div id="clock_div"></div>

    <script src="js/clock.js"></script>
</html>